Electric percussion fuse



March 5, 1929. I UH M N 1,704,302

ELEGTRI C PERCUSS ION FUSE Filed April 16, 1923 Ink/ENTE a M/ A EIR EY- Patented Mar. 5, 1929.

UNITED STATES PATT OFFICE.

HERBERT nfinnnmmm, or SOMMEIRDA, GERMANY, Assrenon 'ro REEINISGHE rmrALLwAAnEN- UNI) MAscHINEnI-ABRIK, or DUSSELDORF-DERENDORF, enn- MANY.

ELEG'IRIC PERCUSSION FUSE.

Application filed April 16, 1928, Serial No. 270,464, and in Germany April 27, 1927.

The invention relates to electric percussion fuses of the type in which the flow of the current from the source of current through the igniting means, viz an incandescent bridge piece, is made adjustable to variable strength by means of a regulating resistance inserted in the circuit of the percussion fuse, whereby an impact ignition with or without delay is obtained according to a greater or smaller resistance amount being switched-in.

According to the invention the fuse comrises two igniting means adapted to be seectively switched into the circuit of its source of current or other accumulator of electric power, one of these igniting meansnew arrangement affords the advantage, that now also a spark igniter may be used as igniting means, WhlCh is of particular advantage in the impact ignition without delay, to increase the quick action of the fuse,

that gneans to reduce the lag of ignition af- 7 ter the impact contact has been closed.

In order to allow of my invention to be more easily understood, a wiring diagram of my improved fuse is-illustrated by way of example in the drawing which accompanies and forms part of this specification. The source of electric power of the fuse is 1 constituted e. g. by an electric condenser a,

which is loaded through its poles a, and a reaching up to the surface of the projectile shell, by a source of current (not shown) arranged separately from the projectile, before or the instant the projectile is fired. A normally open impact contact I) and a throw-over switch a is arranged in the discharge circuit, by which switch either the igniting means (I, or (2 may be switched-in selectively.

Both these igniting means d, and d may be designed as incandescent bridge igniters or as spark igniters. The igniter d operates with delay, whilst 03, operates without delay. To this end the igniter cl, is formed e. g. by an incandescent bridge igniter, be-

fore which a high ohmic resistance is arranged. When the igniter d, has been thrown into the discharge circuit of condenser a by means of switch 0, then, when the impact contact I) is closed by the projectile ittin an aim and the current then flows throug the igniter al the heating wire of the latter is heated up only after a certain lapse of time to the temperature required for the ignition, so that the latter does not take place immediately on impact, but only with a certain delay.

The delay igniter 01 may further be fitted with a heating wire that ignites immediately when the current flows therethrough or with a spark gap that firstly influences a delay compositlon of known type.

The igniting means ol intended to operate without delay, suitably consists of a spark igniter that works more quickly than a bridge igniter and instantaneously ignites upon the impact contact I) being closed, whereby the impact ignition takes place particularly quickly.

The switch a may be desi ned in such a manner, that in its position "no delay, that is when the non-delay igniter d, has been switched in, for the sake of reliable action at the same time also the delay igniter d, is thrown-in, so that, upon the instantaneous percussion ignition failing to act a delay ignition still takes place as with the known mechanical percussion fuses with ad'ustable delay. In a third (illustrated) posltion of the switch a both igniters d, and d, are disconnected from the condenser a. -The handle serving to manipulate switch 0 may be made independent of the latter as to its switch motion, so that even after setting the handle to no delay or delay the switch 0 .firstly perseveres in disconnecting position and automatically arrives in the set position by inertia only when the projectile is fired.

What I claim, is

1. In an electric projectile percussion fuse of the class described a source of current, a circuit connected thereto, an impact contact in said circuit, two electric igniters and means for connecting them selectively to said circuit, one of said igniters being adapted to operate with and the other to operate without delay.

2. In an electric projectile percussion fuse of the class described a source of current, a circuit connected thereto, an impact contact in said circuit, two electric igniters connected in parallel to said circuit, a switch arranged in said circuit and adapted to selectively switch-in one of said igniters, one of them being adapted to operate with and the other to operate Without delay.

3. In an electric projectile percussion fuse of the class described a source of current, a circuit connected thereto, an impact contact in said circuit, two electric igniters connected in parallel to said circuit, a switch arranged in said circuit and adapted to selectively switch-in one of said igniters, one of them being adapted to operate with and the other to operate without delay, said firstnamed igniter comprising a heating wire, and the last-named igniter a spark gap.

4. In an electric projectile percussion fuse of the class dcscribed a source of current, a circuit connected thereto, an impact contact in said circuit, two electric igniters and means for connecting them both selectively and commonly to said circuit, one of said igniters being adapted to operate with and the other to operate without delay.

In testimony whereof I have aflixed my signature.

HERBERT RUHLEMANN. 

